Gate electrode having upper and lower capping patterns

ABSTRACT

Disclosed are semiconductor devices and methods of manufacturing the same. The semiconductor device comprises a gate electrode on a substrate, an upper capping pattern on the gate electrode, and a lower capping pattern between the gate electrode and the upper capping pattern. The lower capping pattern comprises a first portion between the gate electrode and the upper capping pattern, and a plurality of second portions extending from the first portion onto corresponding side surfaces of the upper capping pattern. The upper capping pattern covers a topmost surface of each of the second portions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This U.S. non-provisional application claims the benefit of priorityunder 35 U.S.C. § 119 to Korean Patent Application No. 10-2017-0161937,filed on Nov. 29, 2017, in the Korean Intellectual Property Office, theentire contents of which are hereby incorporated by reference.

BACKGROUND

This disclosure relates to a semiconductor device, and moreparticularly, to a semiconductor device including a field effecttransistor and a method of manufacturing the same.

A semiconductor device includes an integrated circuit consisting ofmetal oxide semiconductor field effect transistors (MOSFETs). As sizesand design rules of semiconductor devices are gradually decreased, sizesof the MOSFETs are also increasingly scaled down. The scale down ofMOSFETs may deteriorate operating characteristics of the semiconductordevice. Accordingly, various research is being developed to fabricate asemiconductor device having excellent performances while overcominglimitations due to integration of the semiconductor device.

SUMMARY

Some embodiments provide a semiconductor device having improvedelectrical characteristics and a method of manufacturing the same.

Some embodiments provide a semiconductor device and a method ofmanufacturing the same in which the method maintains a process margin.

According to exemplary embodiments, the disclosure is directed to asemiconductor device comprising: a gate electrode on a substrate; anupper capping pattern on the gate electrode; and a lower capping patternbetween the gate electrode and the upper capping pattern, wherein thelower capping pattern comprises: a first portion between the gateelectrode and the upper capping pattern; and a plurality of secondportions extending from the first portion onto corresponding sidesurfaces of the upper capping pattern, wherein the upper capping patterncovers a topmost surface of each of the second portions.

According to exemplary embodiments, the disclosure is directed to asemiconductor device comprising: a gate electrode on a substrate; anupper capping pattern on the gate electrode; a lower capping patternbetween the gate electrode and the upper capping pattern; and aninterlayer dielectric layer on the substrate and covering the gateelectrode, the upper capping pattern, and the lower capping pattern,wherein a top surface of the upper capping pattern is located at thesame height relative to the substrate in a vertical direction as that ofa top surface of the interlayer dielectric layer, and wherein a topmostsurface of the lower capping pattern is located at a lower heightrelative to the substrate in the vertical direction than that of the topsurface of the interlayer dielectric layer.

According to exemplary embodiments, the disclosure is directed to amethod of manufacturing a semiconductor device, the method comprising:forming on a substrate a sacrificial gate pattern and an interlayerdielectric layer covering the sacrificial gate pattern; removing thesacrificial gate pattern to form a gap in the interlayer dielectriclayer; forming a gate electrode in the gap; forming on the interlayerdielectric layer a lower capping layer covering an inner surface of thegap and a top surface of the gate electrode; forming in the gap a maskpattern covering a portion of the lower capping layer; removing otherportions of the lower capping layer to form a lower capping pattern inthe gap, wherein the other portions of the lower capping layer are notcovered with the mask pattern; and forming an upper capping patternfilling a remainder of the gap.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a plan view showing a semiconductor device, accordingto exemplary embodiments.

FIG. 2 illustrates a cross-sectional view taken along lines I-I′,II-II′, and III-III′ of FIG. 1.

FIG. 3 illustrates a perspective view showing a gate structure of FIG.1.

FIGS. 4 to 10 illustrate cross-sectional views taken along lines I-I′,II-II′, and III-III′ of FIG. 1, showing a method of manufacturing asemiconductor device, according to exemplary embodiments.

FIG. 11 illustrates a cross-sectional view taken along lines I-I′,II-II′, and III-III′ of FIG. 1, showing a semiconductor device,according to exemplary embodiments.

FIGS. 12 and 13 illustrate cross-sectional views taken along lines I-I′,II-II′, and III-III′ of FIG. 1, showing a method of manufacturing asemiconductor device, according to exemplary embodiments.

FIG. 14 illustrates a cross-sectional view taken along lines I-I′,II-II′, and III-III′ of FIG. 1, showing a semiconductor device,according to exemplary embodiments.

FIG. 15 illustrates a cross-sectional view taken along lines I-I′,II-II′, and III-III′ of FIG. 1, showing a method of manufacturing asemiconductor device, according to exemplary embodiments.

FIG. 16 illustrates a cross-sectional view taken along lines I-I′,II-II′, and III-III′ of FIG. 1, showing a semiconductor device,according to exemplary embodiments.

FIG. 17 illustrates a cross-sectional view taken along lines I-I′,II-II′, and III-III′ of FIG. 1, showing a method of manufacturing asemiconductor device, according to exemplary embodiments.

FIG. 18 illustrates a plan view showing a semiconductor device,according to exemplary embodiments.

FIG. 19 illustrates a cross-sectional view taken along lines I-I′ andII-II′ of FIG. 18.

FIG. 20 illustrates a cross-sectional view taken along lines I-I′ andII-II′ of FIG. 18, showing a semiconductor device, according toexemplary embodiments.

DETAILED DESCRIPTION

Hereinafter, some embodiments will be described in detail in conjunctionwith the accompanying drawings to aid in clearly understanding inventiveconcepts.

FIG. 1 illustrates a plan view showing a semiconductor device, accordingto exemplary embodiments. FIG. 2 illustrates a cross-sectional viewtaken along lines I-I′, II-II′, and III-III′ of FIG. 1. FIG. 3illustrates a perspective view showing a gate structure of FIG. 1.

Referring to FIGS. 1 to 3, a substrate 100 may be provided thereon witha device isolation layer ST defining an active pattern ACT. Thesubstrate 100 may be or may include a silicon substrate, a germaniumsubstrate, or a silicon-on-insulator (SOI) substrate. The deviceisolation layer ST may include, for example, oxide, nitride, oroxynitride. The active pattern ACT may extend in a direction D1 parallelto a top surface of the substrate 100. In some embodiments, asillustrated in FIG. 2, the device isolation layer ST may have a topsurface substantially coplanar with that of the active pattern ACT. Inother embodiments, different from that shown in FIG. 2, the deviceisolation layer ST may expose side surfaces of an upper portion of theactive pattern ACT. In this case, the active pattern ACT may include anupper portion (or fin) exposed by the device isolation layer ST.

The substrate 100 may be provided thereon with a gate structure GSrunning across the active pattern ACT. The gate structure GS may extendin a second direction D2 parallel to the top surface of the substrate100. The first direction D1 and the second direction D2 may intersecteach other and be perpendicular to one another. The gate structure GSmay be provided in plural on the substrate 100. The plurality of gatestructures GS may extend across the active pattern ACT, and may bespaced apart from each other along the first direction D1.

The gate structure GS may include a gate electrode GE extending acrossthe active pattern ACT, a capping pattern CAP on the gate electrode GE,a gate dielectric pattern GI between the gate electrode GE and thesubstrate 100, and gate spacers GSP on side surfaces of the gateelectrode GE. The gate electrode GE may have a linear shape extending inthe second direction D2. The gate spacers GSP may be correspondinglyprovided on opposite side surfaces of the gate electrode GE, and each ofthe gate spacers GSP may extend in the second direction D2 along acorresponding side surface of the gate electrode GE. The gate dielectricpattern GI may extend in the second direction D2 along a bottom surfaceof the gate electrode GE, and may extend in the second direction D2along side surfaces of the gate electrode GE between the gate electrodeGE and each of the gate spacers GSP. The gate electrode GE may includeone or more of conductive metal nitride (e.g., titanium nitride,tantalum nitride, etc.) and metal (e.g., aluminum, tungsten, etc.). Thegate electrode GE may include metallic materials having different workfunctions from each other. The gate dielectric pattern GI may include atleast one of high-k dielectric layers. For example, the gate dielectricpattern GI may include one or more of hafnium oxide, hafnium silicate,zirconium oxide, and zirconium silicate. The gate spacers GSP mayinclude nitride (e.g., silicon nitride).

The capping pattern CAP may extend in the second direction D2 along atop surface of the gate electrode GE. The capping pattern CAP mayinclude an upper capping pattern 120 on the gate electrode GE and alower capping pattern 110 between the gate electrode GE and the uppercapping pattern 120. Each of the lower capping pattern 110 and the uppercapping pattern 120 may extend in the second direction D2 along the topsurface of the gate electrode GE, when viewed in a plan view. The lowercapping pattern 110 may separate the upper capping pattern 120 from thegate electrode GE. For example, the upper capping pattern 120 may bespaced apart from the gate electrode GE across the lower capping pattern110 in a vertical direction. The capping pattern CAP may further includea boundary between the upper capping pattern 120 and the lower cappingpattern 110, and the boundary between the upper capping pattern 120 andthe lower capping pattern 110 may include an oxide.

The lower capping pattern 110 may include a first portion 110P1 betweenthe gate electrode GE and the upper capping pattern 120 in a horizontaldirection and second portions 110P2 extending from the first portion110P1 onto corresponding side surfaces of the upper capping pattern 120in a vertical direction. The second portions 110P2 of the lower cappingpattern 110 may be correspondingly provided on opposite side surfaces ofthe upper capping pattern 120, and each of the second portions 110P2 mayextend in the second direction D2 along a corresponding side surface ofthe upper capping pattern 120. The topmost surface of the lower cappingpattern 110 may be a topmost surface of each of the second portions110P2. In other embodiments, different from that shown, each of thesecond portions 110P2 of the lower capping pattern 110 may have a shapethat is tapered in a direction away from the substrate 100. For example,each of the second portions 110P2 may have a width in the firstdirection D1, and the width in the first direction D1 of each of thesecond portions 110P2 may decrease along the direction away from thesubstrate 100 (i.e., in a vertical direction). The lower capping pattern110 may be shaped like U when viewed in cross-section. The gatedielectric pattern GI may extend between each of the gate spacers GSPand the gate electrode GE, thereby being in contact with the lowercapping pattern 110. For example, topmost surfaces of the gatedielectric pattern GI may contact a lower surface of the lower cappingpattern 110 at region below the second portions 110P2.

It will be understood that when an element is referred to as being“connected” or “coupled” to, or “on” another element, it can be directlyconnected or coupled to, or on the other element or intervening elementsmay be present. In contrast, when an element is referred to as being“directly connected,” “directly coupled,” in or “directly on” anotherelement, there are no intervening elements present. Other words used todescribe the relationship between elements should be interpreted in alike fashion (e.g., “between” versus “directly between,” “adjacent”versus “directly adjacent,” etc.). However, the term “contact,” or “incontact with,” as used herein refers to a direct connection (i.e.,touching) unless the context indicates otherwise.

The upper capping pattern 120 may cover topmost surfaces 110U of thelower capping pattern 110. For example, the upper capping pattern 120may cover the topmost surface 110U of each of the second portions 110P2of the lower capping pattern 110. The upper capping pattern 120 may bein contact with the topmost surfaces 110U of the lower capping pattern110. The topmost surfaces 110U of the lower capping pattern 110 may belocated at a lower height relative to the substrate 100 in a verticaldirection than that of a top surface 120U of the upper capping pattern120. A portion of the upper capping pattern 120 may be interposedbetween the second portions 110P2 of the lower capping pattern 110. Theportion of the upper capping pattern 120 may fill a space between thesecond portions 110P2 of the lower capping pattern 110.

The upper capping pattern 120 may include a body 120BP and a protrusion120PP that protrudes from the body 120BP toward the substrate 100. Thebody 120BP may have a first width W1, and the protrusion 120PP may havea second width W2 less than the first width W1. The first width W1 maybe a maximum width of the body 120BP when measured along the firstdirection D1, and the second width W2 may be a maximum width of theprotrusion 120PP when measured along the first direction D1. In theexample illustrated in FIG. 2, the widths of the body 120BP and theprotrusion 120PP may be constant widths in the vertical direction. Insome embodiments, different from that shown, when each of the secondportions 110P2 of the lower capping pattern 110 has a shape that istapered in the direction away from the substrate 100 in a verticaldirection, the second width W2 of the protrusion 120PP may increase inthe direction away from the substrate 100 in the vertical direction. Theprotrusion 120PP of the upper capping pattern 120 may be interposedbetween the second portions 110P2 of the lower capping pattern 110, andthe body 120BP of the upper capping pattern 120 may cover the topmostsurface 110U of each of the second portions 110P2 of the lower cappingpattern 110. The body 120BP of the upper capping pattern 120 may be incontact with the topmost surface 110U of each of the second portions110P2 of the lower capping pattern 110. The topmost surface 110U of thelower capping pattern 110 may be located at a lower height relative tothe substrate 100 in the vertical direction than that of the top surface120U of the body 120BP of the upper capping pattern 120. Each of thelower capping pattern 110 and the upper capping pattern 120 may includenitride (e.g., silicon nitride).

Source/drain regions SD may be provided in the active pattern ACT onopposite sides of the gate structure GS. For example, the source/drainregions SD may be formed between neighboring ones of the gate spacersGSP in the active pattern ACT. The active pattern ACT may have a portionthat is positioned below the gate structure GS and overlaps the gatestructure GS in the vertical direction, and that portion of the activepattern ACT may be used as a channel region CH. An interlayer dielectriclayer 130 may be provided on the substrate 100, covering the gatestructure GS and the source/drain regions SD. The interlayer dielectriclayer 130 may have a top surface 130U substantially coplanar with thetop surface 120U of the upper capping pattern 120 (or with the topsurface 120U of the body 120BP of the upper capping pattern 120). Forexample, the top surface 130U of the interlayer dielectric layer 130 maybe at the same vertical height as the top surface 120U of the uppercapping pattern 120. The topmost surface 110U of the lower cappingpattern 110 (or the topmost surface 110U of each of the second portions110P2 of the lower capping pattern 110) may be located at a lower heightrelative to the substrate 100 in the vertical direction than that of thetop surface 130U of the interlayer dielectric layer 130. The interlayerdielectric layer 130 may include, for example, a silicon oxide layer.

Contacts 140 may be provided on opposite sides of the gate structure GS.The contacts 140 may penetrate the interlayer dielectric layer 130 tocome into electrical connection with the substrate 100. The contacts 140may be electrically connected to corresponding source/drain regions SDon the opposite sides of the gate structure GS. The contacts 140 mayinclude one or more of doped semiconductor, metal, metal silicide, andconductive metal nitride.

The gate structure GS may include a first region R1 whose opposite sidesare provided with the contacts 140, and a second region R2 whoseopposite sides are provided without the contacts 140. At the firstregion R1 of the gate structure GS, the upper capping pattern 120 may bein contact with the contacts 140. For example, at the first region R1 ofthe gate structure GS, the body 120BP of the upper capping pattern 120may be in contact with the contacts 140. At the second region R2 of thegate structure GS, the gate spacers GSP may extend onto correspondingside surfaces of the capping pattern CAP, and a topmost surface of eachof the gate spacers GSP may be substantially coplanar with the topsurface 130U of the interlayer dielectric layer 130. In someembodiments, the gate spacers GSP may have a shape that tapers as thegate spacers GSP come closer to the top surface 130U of the interlayerdielectric layer 130. Each of the gate spacers GSP may be interposedbetween the capping pattern CAP and the interlayer dielectric layer 130and may be in contact with the capping pattern CAP. For example, at thesecond region R2 of the gate structure GS, each of the second portions110P2 of the lower capping pattern 110 may be interposed between theprotrusion 120PP of the upper capping pattern 120 and each of the gatespacers GSP, while being in contact with each of the gate spacers GSP.At the second region R2 of the gate structure GS, the body 120BP of theupper capping pattern 120 may be in contact with the gate spacers GSP.

The gate structure GS and the source/drain regions SD may constitute afield effect transistor. For example, the gate structure GS and thesource/drain regions SD may constitute a P-type field effect transistor.Although not shown, the interlayer dielectric layer 130 may be providedthereon with wiring lines connected to the contacts 140. The wiringlines (not shown) may be electrically connected through the contacts 140to the source/drain regions SD.

FIGS. 4 to 10 illustrate cross-sectional views taken along lines I-I′,II-II′, and III-III′ of FIG. 1, showing a method of manufacturing asemiconductor device, according to exemplary embodiments.

Referring to FIG. 4, a device isolation layer ST may be formed on asubstrate 100 to define an active pattern ACT. An STI (Shallow TrenchIsolation) process may be used to form the device isolation layer ST.The active pattern ACT may be formed to extend in a first direction D1.

An etch stop layer (not shown) and a sacrificial gate layer (not shown)may be sequentially formed on the substrate 100. The etch stop layer mayinclude, for example, a silicon oxide layer. The sacrificial gate layermay include a material having an etch selectivity to the etch stoplayer. The sacrificial gate layer may include, for example, polysilicon.The sacrificial gate layer may be patterned to form a sacrificial gatepattern 160. The sacrificial gate pattern 160 may be formed to extend ina second direction D2 and to run across the active pattern ACT. Theformation of the sacrificial gate pattern 160 may include forming a gatemask pattern 170 on the sacrificial gate layer and etch the sacrificialgate layer by using the gate mask pattern 170 as an etching mask. Thegate mask pattern 170 may include, for example, silicon nitride. Theetching of the sacrificial gate layer may include performing an etchingprocess having an etch selectivity to the etch stop layer. After thesacrificial gate pattern 160 is formed, the etch stop layer may beremoved from opposite sides of the sacrificial gate pattern 160 suchthat an etch stop pattern 150 may be formed below the sacrificial gatepattern 160. The etch stop pattern 150 may extend in the seconddirection D2 along a bottom surface of the sacrificial gate pattern 160.

Gate spacers GSP may be correspondingly formed on side surfaces of thesacrificial gate pattern 160. The gate spacers GSP may include, forexample, silicon nitride. The formation of the gate spacers GSP mayinclude forming a gate spacer layer (not shown) on the substrate 100 onwhich the sacrificial gate pattern 160 is formed and anisotropicallyetching the gate spacer layer.

Source/drain regions SD may be formed in the active pattern ACT onopposite sides of the sacrificial gate pattern 160. The formation of thesource/drain regions SD may include, for example, performing a selectiveepitaxial growth process to form epitaxial patterns in the activepattern ACT on opposite sides of the sacrificial gate pattern 160.Alternatively, the formation of the source/drain regions SD may includeperforming an ion implantation process to form impurity-doped regions inthe active pattern ACT on opposite sides of the sacrificial gate pattern160.

Referring to FIG. 5, an interlayer dielectric layer 130 may be formed onthe substrate 100 to cover the sacrificial gate pattern 160 and thesource/drain regions SD. The interlayer dielectric layer 130 mayinclude, for example, silicon oxide. The interlayer dielectric layer 130may be planarized to expose a top surface of the sacrificial gatepattern 160 and top surfaces of the gate spacers GSP. The gate maskpattern 170 may be removed when the interlayer dielectric layer 130 isplanarized.

Referring to FIG. 6, the sacrificial gate pattern 160 and the etch stoppattern 150 may be removed. Accordingly, a gap 180 may be formed betweenthe gate spacers GSP in the interlayer dielectric layer 130. Forexample, the gap 180 may be formed between each pair of gate spacersGSP. The formation of the gap 180 may include etching the sacrificialgate pattern 160 and the etch stop pattern 150 by performing an etchingprocess having an etch selectivity to the interlayer dielectric layer130 and the gate spacers GSP.

A gate dielectric pattern GI and a gate electrode GE may be formed inthe gap 180. For example, the formation of the gate dielectric patternGI and the gate electrode GE may include forming on the interlayerdielectric layer 130 a gate dielectric layer (not shown) partiallyfilling the gap 180, forming on the gate dielectric layer a gateelectrode layer (not shown) completely filling the gap 180, andplanarizing the gate dielectric layer and the gate electrode layer untila top surface of the interlayer dielectric layer 130 is exposed. Theplanarization process may expose the top surfaces of the gate spacersGSP. The gate electrode layer may be etched on its upper portion untilthe gate electrode layer reaches a desired thickness in the gap 180, toform the gate electrode GE. In addition, the gate dielectric layer maybe etched on its upper portion not covered with the gate electrode GE,to form the gate dielectric pattern GI. The gate dielectric pattern GImay be interposed between the gate electrode GE and the substrate 100,and may extend between the gate electrode GE and each of the gatespacers GSP. In some embodiments, the gate dielectric pattern GI mayhave a topmost surface at substantially the same level relative to thesubstrate 100 in the vertical direction as that of a top surface of thegate electrode GE. The gate electrode GE and the gate dielectric patternGI may fill a lower portion of the gap 180.

Referring to FIG. 7, a lower capping layer 182 may be formed on theinterlayer dielectric layer 130 to partially fill an upper portion ofthe gap 180. The lower capping layer 182 may be formed to conformallycover an inner surface of the upper portion of the gap 180, the topsurface of the gate electrode GE, the topmost surface of the gatedielectric pattern GI. The formation of the lower capping layer 182 mayinclude performing a first deposition process under an atmosphere whoseH₂ plasma density is relatively low. For example, the first depositionprocess may include indirect H₂ plasma treatment or not include H₂plasma treatment. The first deposition process may be or may include anatomic layer deposition process performed under an atmosphere whose H₂plasma density is relatively low. The lower capping layer 182 mayinclude, for example, silicon nitride.

A mask pattern 185 may be formed in the gap 180 to cover a portion ofthe lower capping layer 182. The formation of the mask pattern 185 mayinclude forming a mask layer filling the reminder of the upper portionof the gap 180 and etching the mask layer until the mask layer reaches adesired thickness in the vertical direction in the upper portion of thegap 180. The mask pattern 185 may include, for example, aspin-on-hardmask (SOH) material (e.g., a carbon-containing layer).

Referring to FIG. 8, other portions of the lower capping layer 182,which is not covered with the mask pattern 185, may be removed to form alower capping pattern 110. The lower capping pattern 110 may beinterposed between the mask pattern 185 and the gate electrode GE andbetween the mask pattern 185 and the gate dielectric pattern GI, and mayextend between the mask pattern 185 and each of the gate spacers GSP. Atopmost surface 110U of the lower capping pattern 110 may be located atsubstantially the same level relative to the substrate 100 in thevertical direction as that of a top surface of the mask pattern 185.

Referring to FIG. 9, the mask pattern 185 may be removed. The maskpattern 185 may be removed by performing an ashing process and/or astrip process. After the mask pattern 185 is removed, an upper cappinglayer 187 may be formed on the interlayer dielectric layer 130 to fillthe remainder of the gap 180. The formation of the upper capping layer187 may include performing a second deposition process under anatmosphere whose H₂ plasma density is relatively high. For example, thesecond deposition process may include direct H₂ plasma treatment. Thesecond deposition process may be or may include an atomic layerdeposition process performed under an atmosphere whose H₂ plasma densityis relatively high. The upper capping layer 187 may include, forexample, silicon nitride. As the second deposition process is performedunder an atmosphere whose H₂ plasma density is relatively higher thanthat of an atmosphere under which the first deposition process isperformed, the upper capping layer 187 may have an impurity content lessthan that of the lower capping layer 182. Accordingly, the upper cappinglayer 187 may be formed to have a density greater than that of the lowercapping layer 182.

Referring to FIG. 10, the upper capping layer 187 may be planarizeduntil the interlayer dielectric layer 130 is exposed. As a result of theplanarization process, an upper capping pattern 120 may be formedlocally in the gap 180. The lower capping pattern 110 and the uppercapping pattern 120 may constitute a capping pattern CAP. A gatestructure GS may be constituted or formed by the gate electrode GE, thegate dielectric pattern GI, the capping pattern CAP, and the gatespacers GSP.

Contact holes 140H may be formed in the interlayer dielectric layer 130on opposite sides of the gate structure GS. The contact holes 140H mayexpose the source/drain regions SD on opposite sides of the gatestructure GS. The formation of the contact holes 140H may includeperforming an etching process to etch the interlayer dielectric layer130 under an etching condition that has an etch selectivity to thecapping pattern CAP and the gate spacers GSP. As the upper capping layer187 is formed to have a density greater than that of the lower cappinglayer 182, when the etching process is performed to form the contactholes 140H, the upper capping pattern 120 may exhibit etching resistancegreater than that of the lower capping pattern 110.

In general, a capping pattern on a gate electrode may be formed as asingle pattern including silicon nitride. The capping pattern may beformed by a deposition process performed under an atmosphere whose H₂plasma density is relatively high. In this case, when the depositionprocess is performed, hydrogen may diffuse into the gate electrode, andas a result, it may be difficult to control a threshold voltage of thegate electrode.

According to certain embodiments, the capping pattern CAP may be formedas a multi-layered structure including the upper capping pattern 120 andthe lower capping pattern 110. The upper capping pattern 120 may beformed by the second deposition process performed under an atmospherewhose H₂ plasma density is relatively high, and the lower cappingpattern 110 may be formed by the first deposition process performedunder an atmosphere whose H₂ plasma density is relatively low. In thiscase, hydrogen may minimize or decrease in diffusion into the gateelectrode GE during the first deposition process, and thereafter thelower capping pattern 110 may suppress or prevent hydrogen fromdiffusing into the gate electrode GE during the second depositionprocess for forming the upper capping pattern 120. Accordingly, it maybe easier to control a threshold voltage of the gate electrode GE.

In addition, when the etching process is performed to form the contactholes 140H, the upper capping pattern 120 may exhibit etching resistancegreater than that of the lower capping pattern 110. The upper cappingpattern 120 may be formed to cover the topmost surface 110U of the lowercapping pattern 110, and in this case, the lower capping pattern 110 maybe least exposed during the etching process for forming the contactholes 140H. Accordingly, during the etching process for forming thecontact holes 140H, it may be possible to minimize or prevent loss ofthe capping pattern CAP and to keep a process margin for the etchingprocess.

Consequently, not only a process margin may be securely obtained inmanufacturing a semiconductor device, but the semiconductor device mayhave improvement in electrical characteristics.

Referring back to FIGS. 1 and 2, contacts 140 may be formed in thecontact holes 140H. The formation of the contacts 140 may includeforming on the interlayer dielectric layer 130 a conductive layerfilling the contact holes 140H and planarizing the conductive layeruntil the interlayer dielectric layer 130 is exposed. The contacts 140may include one or more of, for example, doped semiconductor, metal,metal silicide, and conductive metal nitride. Although not shown, wiringlines (not shown) may be formed on the interlayer dielectric layer 130to come into connection with the contacts 140. The wiring lines may beelectrically connected through the contacts 140 to the source/drainregions SD.

FIG. 11 illustrates a cross-sectional view taken along lines I-I′,II-II′, and III-III′ of FIG. 1, showing a semiconductor device,according to exemplary embodiments. For brevity of explanation, thefollowing description will focus on differences from the semiconductordevice discussed with reference to FIGS. 1 to 3.

Referring to FIGS. 1 and 11, the capping pattern CAP may include theupper capping pattern 120 and the lower capping pattern 110. The uppercapping pattern 120 may be spaced apart from the gate electrode GEacross the lower capping pattern 110. In addition, the upper cappingpattern 120 may be spaced apart from each of the gate spacers GSP acrossthe lower capping pattern 110. For example, the lower capping pattern110 may be between the upper capping pattern 120 and the gate electrodeGE and between the upper capping pattern 120 and the gate spacers GSP.

The lower capping pattern 110 may include the first portion 110P1between the gate electrode GE and the upper capping pattern 120 and thesecond portions 110P2 extending from the first portion 110P1 ontocorresponding side surfaces of the upper capping pattern 120. The lowercapping pattern 110 may be shaped like U when viewed in cross-section.The gate dielectric pattern GI may extend between each of the gatespacers GSP and the gate electrode GE, thereby being in contact with thelower capping pattern 110. For example, topmost surfaces of the gatedielectric pattern GI may be in contact with a lower surface of thelower capping pattern 110. Further, each of the gate spacers GSP mayhave a topmost surface in contact with the lower capping pattern 110. Insome embodiments, the topmost surface of the gate spacers GSP may be aslanted surface that extends from one side surface of the gate spacerGSP to another side surface of the gate spacer GSP and faces the lowercapping pattern 110.

The upper capping pattern 120 may include the body 120BP and theprotrusion 120PP that protrudes from the body 120BP toward the substrate100. The body 120BP may have the first width W1, and the protrusion120PP may have the second width W2 less than the first width W1. In someembodiments, the first width W1 may be a first range of widths and thesecond width W2 may be a second range of widths, and the first range ofwidths may be greater than the second range of widths. For example, thebody 120BP may have a first width W1 that decreases in a verticaldirection (e.g., the first width is greater at a bottom of the body120BP and smaller at a top of the body 120BP), and the protrusion 120PPmay have a second width W2 that increases in the vertical direction(e.g., the second width is smaller at a bottom of the protrusion 120PPand greater at a top of the protrusion 120PP). In this example, thewidest first width W1 of the body 120BP is greater than the widestsecond width W2 of the protrusion 120PP.

The protrusion 120PP of the upper capping pattern 120 may be interposedbetween the second portions 110P2 of the lower capping pattern 110, andportions of the body 120BP of the upper capping pattern 120 may coverthe topmost surface 110U of each of the second portions 110P2 of thelower capping pattern 110. The topmost surface 110U of the lower cappingpattern 110 may be located at a lower height relative to the substrate100 in the vertical direction than that of the top surface 120U of thebody 120BP of the upper capping pattern 120. The top surface 130U of theinterlayer dielectric layer 130 may be substantially coplanar with thetop surface 120U of the upper capping pattern 120 (or with the topsurface 120U of the body 120BP of the upper capping pattern 120).

The gate structure GS may include the first region R1 whose oppositesides are provided with the contacts 140 and the second region R2 whoseopposite sides are provided without the contacts 140. At the firstregion R1 of the gate structure GS, the upper capping pattern 120 may bein contact with the contacts 140. For example, at the first region R1 ofthe gate structure GS, the capping pattern CAP may be in contact withthe contacts 140. For example, at the first region R1 of the gatestructure GS, each of the second portions 110P2 of the lower cappingpattern 110 may be in contact with the contacts 140, and may beinterposed between the contacts 140 and the protrusion 120PP of theupper capping pattern 120. The second portions 110P2 of the lowercapping pattern 110 may separate the protrusion 120PP of the uppercapping pattern 120 from the contacts 140. At the first region R1 of thegate structure GS, the body 120BP of the upper capping pattern 120 maybe in contact with the contacts 140. At the second region R2 of the gatestructure GS, the capping pattern CAP may be in contact with theinterlayer dielectric layer 130. For example, at the second region R2 ofthe gate structure GS, each of the second portions 110P2 of the lowercapping pattern 110 may be in contact with the interlayer dielectriclayer 130, and may be interposed between the interlayer dielectric layer130 and the protrusion 120PP of the upper capping pattern 120. Thesecond portions 110P2 of the lower capping pattern 110 may separate theprotrusion 120PP of the upper capping pattern 120 from the interlayerdielectric layer 130. At the second region R2 of the gate structure GS,the body 120BP of the upper capping pattern 120 may be in contact withthe interlayer dielectric layer 130.

FIGS. 12 and 13 illustrate cross-sectional views taken along lines I-I′,II-II′, and III-III′ of FIG. 1, showing a method of manufacturing asemiconductor device, according to exemplary embodiments. For example,FIGS. 12 and 13 illustrate an exemplary method of manufacturing thesemiconductor device of FIG. 11. For brevity of explanation, thefollowing description will focus on differences from the manufacturingmethod discussed with reference to FIGS. 4 to 10.

As discussed with reference to FIGS. 4 to 6, the substrate 100 may beprovided thereon with the device isolation layer ST defining the activepattern ACT and the sacrificial gate pattern 160 running across theactive pattern ACT. The etch stop pattern 150 may be formed below thesacrificial gate pattern 160, and the gate spacers GSP may be formed oncorresponding side surfaces of the sacrificial gate pattern 160. Thesource/drain regions SD may be formed in the active pattern ACT onopposite sides of the sacrificial gate pattern 160, and the interlayerdielectric layer 130 may be formed to cover the sacrificial gate pattern160 and the source/drain regions SD. The sacrificial gate pattern 160and the etch stop pattern 150 may be removed to form the gap 180 betweenthe gate spacers GSP in the interlayer dielectric layer 130. The gateelectrode GE and the gate dielectric pattern GI may be formed to fill alower portion of the gap 180.

Referring to FIG. 12, upper portions of the gate spacers GSP may beremoved, and thus the interlayer dielectric layer 130 may be providedtherein with a recess region 181 exposing an inner surface of theinterlayer dielectric layer 130. The recess region 181 may be defined bythe inner surface of the interlayer dielectric layer 130, a top surfaceof the gate electrode GE, a topmost surface of the gate dielectricpattern GI, and topmost surfaces of the gate spacers GSP. The removal ofthe upper portions of the gate spacers GSP may include performing anetching process having an etch selectivity to the interlayer dielectriclayer 130, the gate electrode GE, and the gate dielectric pattern GI.

The lower capping layer 182 may be formed on the interlayer dielectriclayer 130 to partially fill the recess region 181. The lower cappinglayer 182 may be formed to conformally cover an inner surface of therecess region 181. The mask pattern 185 may be formed in the recessregion 181 to partially cover the lower capping layer 182. The formationof the lower capping layer 182 and the mask pattern 185 may besubstantially the same as the manufacturing method discussed withreference to FIG. 7.

Referring to FIG. 13, other portions of the lower capping layer 182,which is not covered with the mask pattern 185, may be removed to formthe lower capping pattern 110. The lower capping pattern 110 may beinterposed between the mask pattern 185 and the gate electrode GE andbetween the mask pattern 185 and the gate dielectric pattern GI, and mayextend onto side surfaces of the mask pattern 185. The topmost surface110U of the lower capping pattern 110 may be located at substantiallythe same level relative to the substrate 100 in the vertical directionas that of a top surface of the mask pattern 185.

Subsequent processes may be substantially the same as the manufacturingmethod discussed with reference to FIGS. 2, 9, and 10.

FIG. 14 illustrates a cross-sectional view taken along lines I-I′,II-II′, and III-III′ of FIG. 1, showing a semiconductor device,according to exemplary embodiments. For brevity of explanation, thefollowing description will focus on differences from the semiconductordevice discussed with reference to FIGS. 1 to 3.

Referring to FIGS. 1 and 14, the capping pattern CAP may include theupper capping pattern 120 on the gate electrode GE and the lower cappingpattern 110 between the gate electrode GE and the upper capping pattern120. Each of the lower capping pattern 110 and the upper capping pattern120 may extend in the second direction D2 along the top surface of thegate electrode GE, when viewed in plan. The upper capping pattern 120may be spaced apart from the gate electrode GE across the lower cappingpattern 110. For example, the lower capping pattern 110 may be betweenthe upper capping pattern 120 and the gate electrode GE and between theupper capping pattern 120 and the gate dielectric pattern GI.

When viewed in cross-section, each of the lower capping pattern 110 andthe upper capping pattern 120 may have a rectangular shape. The gatedielectric pattern GI may extend between each of the gate spacers GSPand the gate electrode GE, thereby being in contact with the lowercapping pattern 110. For example, topmost surfaces of the gatedielectric pattern GI may be in contact with a bottom surface of thelower capping pattern 110. The upper capping pattern 120 may cover thetopmost surface 110U of the lower capping pattern 110, and the topsurface 130U of the interlayer dielectric layer 130 may be substantiallycoplanar with the top surface 120U of the upper capping pattern 120. Thetopmost surface 110U of the lower capping pattern 110 may be located ata lower height relative to the substrate 100 in the vertical directionthan that of the top surface 130U of the interlayer dielectric layer130. The upper capping pattern 120 may be in contact with the topmostsurface 110U of the lower capping pattern 110.

The gate structure GS may include the first region R1 whose oppositesides are provided with the contacts 140 and the second region R2 whoseopposite sides are provided without the contacts 140. At the firstregion R1 of the gate structure GS, the upper capping pattern 120 may bein contact with the contacts 140. At the second region R2 of the gatestructure GS, the gate spacers GSP may extend onto corresponding sidesurfaces of the capping pattern CAP, and a topmost surface of each ofthe gate spacers GSP may be substantially coplanar with the top surface130U of the interlayer dielectric layer 130. Each of the gate spacersGSP may be interposed between the capping pattern CAP and the interlayerdielectric layer 130, and in contact with the lower capping pattern 110and the upper capping pattern 120.

FIG. 15 illustrates a cross-sectional view taken along lines I-I′,II-II′, and III-III′ of FIG. 1, showing a method of manufacturing asemiconductor device, according to exemplary embodiments. For example,FIG. 15 illustrates an exemplary method of manufacturing thesemiconductor device of FIG. 14. For brevity of explanation, thefollowing description will focus on differences from the manufacturingmethod discussed with reference to FIGS. 4 to 10.

As discussed with reference to FIGS. 4 to 6, the substrate 100 may beprovided thereon with the device isolation layer ST defining the activepattern ACT and the sacrificial gate pattern 160 running across theactive pattern ACT. The etch stop pattern 150 may be formed below thesacrificial gate pattern 160, and the gate spacers GSP may be formed oncorresponding side surfaces of the sacrificial gate pattern 160. Thesource/drain regions SD may be formed in the active pattern ACT onopposite sides of the sacrificial gate pattern 160, and the interlayerdielectric layer 130 may be formed to cover the sacrificial gate pattern160 and the source/drain regions SD. The sacrificial gate pattern 160and the etch stop pattern 150 may be removed to form the gap 180 betweenthe gate spacers GSP. The gate electrode GE and the gate dielectricpattern GI may be formed to fill a lower portion of the gap 180.

Referring to FIG. 15, a lower capping layer (not shown) may be formed onthe interlayer dielectric layer 130 to fill an upper portion of the gap180. The lower capping layer may be formed to substantially completelyfill the upper portion of the gap 180. The formation of the lowercapping layer may include performing a first deposition process. Thefirst deposition process may be performed under an atmosphere whose H₂plasma density is relatively low. For example, the first depositionprocess may include indirect H₂ plasma treatment or not include H₂plasma treatment. The lower capping layer may include, for example,silicon nitride. The lower capping layer may be etched until reaching adesired thickness or depth in the vertical direction in the gap 180 toform the lower capping pattern 110.

Subsequent processes may be substantially the same as the manufacturingmethod discussed with reference to FIGS. 2, 9, and 10.

FIG. 16 illustrates a cross-sectional view taken along lines I-I′,II-II′, and III-III′ of FIG. 1, showing a semiconductor device accordingto exemplary embodiments. For brevity of explanation, the followingdescription will focus on differences from the semiconductor devicediscussed with reference to FIGS. 1 to 3.

Referring to FIGS. 1 and 16, the capping pattern CAP may include theupper capping pattern 120 on the gate electrode GE and the lower cappingpattern 110 between the gate electrode GE and the upper capping pattern120. Each of the lower capping pattern 110 and the upper capping pattern120 may extend in the second direction D2 along the top surface of thegate electrode GE, when viewed in plan. The upper capping pattern 120may be spaced apart from the gate electrode GE across the lower cappingpattern 110. In addition, the upper capping pattern 120 may be spacedapart from each of the gate spacers GSP across the lower capping pattern110. For example, the lower capping pattern 110 may be between the uppercapping pattern 120 and the gate electrode GE and between the uppercapping pattern 120 and the gate spacers GSP.

The gate dielectric pattern GI may extend between each of the gatespacers GSP and the gate electrode GE, thereby being in contact with thelower capping pattern 110. Each of the gate spacers GSP may have atopmost surface in contact with the lower capping pattern 110. The uppercapping pattern 120 may cover the topmost surface 110U of the lowercapping pattern 110, and the top surface 130U of the interlayerdielectric layer 130 may be substantially coplanar with the top surface120U of the upper capping pattern 120. The topmost surface 110U of thelower capping pattern 110 may be located at a lower height relative tothe substrate 100 in the vertical direction than that of the top surface130U of the interlayer dielectric layer 130. The upper capping pattern120 may be in contact with the topmost surface 110U of the lower cappingpattern 110. In some embodiments, the topmost surface of the gatespacers GSP may be a slanted surface that extends from one side surfaceof the gate spacer GSP to another side surface of the gate spacer GSPand faces the lower capping pattern 110.

The gate structure GS may include the first region R1 whose oppositesides are provided with the contacts 140 and the second region R2 whoseopposite sides are provided without the contacts 140. At the firstregion R1 of the gate structure GS, the upper capping pattern 120 may bein contact with the contacts 140. At the second region R2 of the gatestructure GS, the lower capping pattern 110 and the upper cappingpattern 120 may be in contact with the interlayer dielectric layer 130.

FIG. 17 illustrates a cross-sectional view taken along lines I-I′,II-II′, and III-III′ of FIG. 1, showing a method of manufacturing asemiconductor device according to exemplary embodiments. For example,FIG. 17 illustrates an exemplary method of manufacturing thesemiconductor device of FIG. 16. For brevity of explanation, thefollowing description will focus on differences from the manufacturingmethod discussed with reference to FIGS. 4 to 10.

As discussed with reference to FIGS. 4 to 6, the substrate 100 may beprovided thereon with the device isolation layer ST defining the activepattern ACT and the sacrificial gate pattern 160 running across theactive pattern ACT. The etch stop pattern 150 may be formed below thesacrificial gate pattern 160, and the gate spacers GSP may be formed oncorresponding side surfaces of the sacrificial gate pattern 160. Thesource/drain regions SD may be formed in the active pattern ACT onopposite sides of the sacrificial gate pattern 160, and the interlayerdielectric layer 130 may be formed to cover the sacrificial gate pattern160 and the source/drain regions SD. The sacrificial gate pattern 160and the etch stop pattern 150 may be removed to form the gap 180 betweenthe gate spacers GSP. The gate electrode GE and the gate dielectricpattern GI may be formed to fill a lower portion of the gap 180.

Referring to FIG. 17, upper portions of the gate spacers GSP may beremoved, and thus the interlayer dielectric layer 130 may be providedtherein with a recess region 181 exposing an inner surface of theinterlayer dielectric layer 130. The recess region 181 may be defined bythe inner surface of the interlayer dielectric layer 130, a top surfaceof the gate electrode GE, a topmost surface of the gate dielectricpattern GI, and topmost surfaces of the gate spacers GSP. The removal ofthe upper portions of the gate spacers GSP may include performing anetching process having an etch selectivity to the interlayer dielectriclayer 130, the gate electrode GE, and the gate dielectric pattern GI.

A lower capping layer (not shown) may be formed on the interlayerdielectric layer 130 to fill the recess region 181. The lower cappinglayer may be formed to substantially completely fill the recess region181. The formation of the lower capping layer may include performing afirst deposition process. The first deposition process may be performedunder an atmosphere whose H₂ plasma density is relatively low. Forexample, the first deposition process may include indirect H₂ plasmatreatment or not include H₂ plasma treatment. The lower capping layermay include, for example, silicon nitride. The lower capping layer maybe etched until reaching a desired thickness or depth in the verticaldirection in the recess region 181 to form the lower capping pattern110.

Subsequent processes may be substantially the same as the manufacturingmethod discussed with reference to FIGS. 2, 9, and 10.

FIG. 18 illustrates a plan view showing a semiconductor device accordingto exemplary embodiments. FIG. 19 illustrates a cross-sectional viewtaken along lines I-I′ and II-II′ of FIG. 18. For brevity ofexplanation, the following description will focus on differences fromthe semiconductor device discussed with reference to FIGS. 1 to 3.

Referring to FIGS. 18 and 19, the gate structure GS may include a firstgate structure GS1 overlapping a first channel region CH1 and a secondgate structure GS2 overlapping a second channel region CH2. The firstchannel region CH1 may have a channel length (e.g., a length in thedirection D1) less than a channel length (e.g., a length in thedirection D1) of the second channel region CH2. In some embodiments,each of the first gate structure GS1 and the second gate structure GS2may include the gate electrode GE, the gate dielectric pattern GI, thegate spacers GSP, and the capping pattern CAP. The capping pattern CAPmay include the upper capping pattern 120 and the lower capping pattern110. The first gate structure GS1 and the second gate structure GS2 maybe configured substantially the same as each other, except for differentgate lengths from each other. For example, in the embodiment of FIGS. 18and 19, the width in the direction D1 of the first gate structure GS1may be smaller than the width in the direction D1 of the second gatestructure GS2.

FIG. 20 illustrates a cross-sectional view taken along lines I-I′ andII-II′ of FIG. 18, showing a semiconductor device according to exemplaryembodiments. For brevity of explanation, the following description willfocus on differences from the semiconductor device discussed withreference to FIGS. 1 to 3.

Referring to FIGS. 18 and 20, the gate structure GS may include a firstgate structure GS1 overlapping a first channel region CH1 and a secondgate structure GS2 overlapping a second channel region CH2. The firstchannel region CH1 may have a channel length (e.g., a length in thedirection D1) less than a channel length (e.g., a length in thedirection D1) of the second channel region CH2. In some embodiments,each of the first gate structure GS1 and the second gate structure GS2may include the gate electrode GE, the gate dielectric pattern GI, andthe gate spacers GSP. The first gate structure GS1 may include thecapping pattern CAP. The capping pattern CAP may include the uppercapping pattern 120 and the lower capping pattern 110. In contrast, thesecond gate structure GS2 may include a single-layered capping patternCAP_1. The single-layered capping pattern CAP_1 may include the samematerial as that of the upper capping pattern 120, and may be formed byperforming a deposition process the same as that for forming the uppercapping pattern 120. The lower capping pattern 110 may be selectivelyprovided only to the first gate structure GS1. The single-layeredcapping pattern CAP_1 may be in contact with the gate electrode GE andthe gate dielectric pattern GI that are included in the second gatestructure GS2. Each of the gate spacers GSP included in the second gatestructure GS2 may be interposed between the single-layered cappingpattern CAP_1 and the interlayer dielectric layer 130.

According to certain exemplary embodiments, the capping pattern CAP maybe formed as a multi-layered structure including the upper cappingpattern 120 and the lower capping pattern 110. The lower capping pattern110 may be formed by the first deposition process performed under anatmosphere whose H₂ plasma density is relatively low. In this case,hydrogen may minimize or decrease in diffusion into the gate electrodeGE during the first deposition process, and thereafter the lower cappingpattern 110 may suppress or prevent hydrogen from diffusing into thegate electrode GE during the second deposition process for forming theupper capping pattern 120. Accordingly, it may be easy to control athreshold voltage of the gate electrode GE.

In addition, when the etching process is performed to form the contactholes 140H, the upper capping pattern 120 may exhibit etching resistancegreater than that of the lower capping pattern 110. The upper cappingpattern 120 may be formed to cover the topmost surface 110U of the lowercapping pattern 110, and therefore, the capping pattern CAP may beminimized or prevented from loss during the etching process for formingthe contact holes 140H. Accordingly, a process margin may be kept duringthe etching process for forming the contact holes 140H

Consequently, not only a process margin may be securely obtained inmanufacturing a semiconductor device, but the semiconductor device mayhave improvement in electrical characteristics.

The aforementioned description provides exemplary embodiments forexplaining inventive concepts. Therefore, inventive concepts are notlimited to the embodiments described above, and it will be understood byone of ordinary skill in the art that variations in form and detail maybe made therein without departing from the spirit and essential featuresof inventive concepts.

What is claimed is:
 1. A semiconductor device comprising: a gateelectrode on a substrate; an upper capping pattern on the gateelectrode; a lower capping pattern between the gate electrode and theupper capping pattern; and a plurality of gate spacers on correspondingside surfaces of the gate electrode and laterally overlapping the gateelectrode, wherein the lower capping pattern comprises: a first portionbetween the gate electrode and the upper capping pattern; and aplurality of second portions extending from the first portion ontocorresponding side surfaces of the upper capping pattern, wherein theupper capping pattern comprises: a body; and a protrusion extending fromthe body toward the substrate, wherein the protrusion is interposedbetween the second portions of the lower capping pattern, and the bodycovers a topmost surface of each of the second portions, wherein a sidesurface of the body of the upper capping pattern is aligned with a sidesurface of each of the second portions of the lower capping pattern, andwherein each of the plurality of gate spacers is in contact with theside surface of the body and the side surface of each of the secondportions.
 2. The device of claim 1, wherein at least a portion of theupper capping pattern fills a space between the second portions of thelower capping pattern.
 3. The device of claim 2, wherein the topmostsurface of each of the second portions of the lower capping pattern islocated at a lower height relative to the substrate in a verticaldirection than that of a top surface of the upper capping pattern. 4.The device of claim 3, further comprising: an interlayer dielectriclayer on the substrate and covering the gate electrode, the lowercapping pattern, and the upper capping pattern, wherein the top surfaceof the upper capping pattern is coplanar with a top surface of theinterlayer dielectric layer, and wherein the topmost surface of each ofthe second portions of the lower capping pattern is located at a lowerheight relative to the substrate in a vertical direction than that ofthe top surface of the interlayer dielectric layer.
 5. The device ofclaim 1, further comprising: a plurality of contacts electricallyconnected to the substrate on opposite sides of the gate electrode,wherein the gate electrode, the lower capping pattern, and the uppercapping pattern constitute a gate structure, wherein the gate structurecomprises: a first region whose opposite sides are provided with thecontacts; and a second region whose opposite sides are provided withoutthe contacts, and wherein the body of the upper capping pattern is incontact with the contacts at the first region of the gate structure. 6.The device of claim 5, wherein, at the second region of the gatestructure, each of the second portions of the lower capping pattern isinterposed between the protrusion of the upper capping pattern and acorresponding one of the gate spacers.
 7. The device of claim 1, whereinthe gate electrode is a first gate electrode, wherein the upper cappingpattern and the lower capping pattern constitute a multi-layered cappingpattern on the first gate electrode, wherein the semiconductor devicefurther comprises: a second gate electrode on the substrate; and anadditional capping pattern on the second gate electrode, wherein theadditional capping pattern has a structure different from that of themulti-layered capping pattern, and wherein a first channel length in ahorizontal direction of a first channel region overlapping the firstgate electrode is less than a second channel length in the horizontaldirection of a second channel region overlapping the second gateelectrode.
 8. A semiconductor device comprising: a gate electrode on asubstrate; an upper capping pattern on the gate electrode; a lowercapping pattern between the gate electrode and the upper capping patternand in contact with the upper capping pattern; a plurality of gatespacers on corresponding side surfaces of the gate electrode andlaterally overlapping the gate electrode; and an interlayer dielectriclayer on the substrate and covering the gate electrode, the uppercapping pattern, and the lower capping pattern, wherein a top surface ofthe upper capping pattern is located at the same height relative to thesubstrate in a vertical direction as that of a top surface of theinterlayer dielectric layer, and wherein a topmost surface of the lowercapping pattern is located at a lower height relative to the substratein the vertical direction than that of the top surface of the interlayerdielectric layer, wherein the upper capping pattern includes a body anda protrusion, the protrusion extending from the body toward thesubstrate, wherein each of the plurality of gate spacers is in contactwith the lower capping pattern and the body of the upper cappingpattern, and wherein each of the plurality of gate spacers is spacedapart from the protrusion of the upper capping pattern with the lowercapping pattern interposed therebetween.
 9. The device of claim 8,wherein the upper capping pattern is in contact with the topmost surfaceof the lower capping pattern.
 10. The device of claim 8, wherein thelower capping pattern comprises: a first portion between the gateelectrode and the upper capping pattern; and a plurality of secondportions extending from the first portion onto corresponding sidesurfaces of the upper capping pattern, wherein the topmost surface ofthe lower capping pattern is a topmost surface of each of the secondportions of the lower capping pattern.
 11. The device of claim 10,wherein the body of the upper capping pattern has a first width in ahorizontal direction; and wherein the protrusion of the upper cappingpattern has a second width in the horizontal direction less than thefirst width, the protrusion extending from the body toward the substratein the vertical direction, wherein the protrusion is interposed betweenthe second portions of the lower capping pattern, and wherein the bodycovers the topmost surface of each of the second portions.
 12. Thedevice of claim 11, wherein the topmost surface of each of the secondportions of the lower capping pattern is located at a lower heightrelative the substrate in the vertical direction than that of a topsurface of the body of the upper capping pattern.
 13. The device ofclaim 11, wherein each of the second portions of the lower cappingpattern is interposed between the protrusion of the upper cappingpattern and a corresponding one of the gate spacers.
 14. The device ofclaim 8, further comprising: a gate dielectric pattern between thesubstrate and the gate electrode, wherein the gate dielectric patternextends in the vertical direction onto side surfaces of the gateelectrode and is in contact with the lower capping pattern.
 15. Thedevice of claim 8, wherein the gate electrode is a first gate electrode,wherein the upper capping pattern and the lower capping patternconstitute a multi-layered capping pattern on the first gate electrode,wherein the semiconductor device further comprises: a second gateelectrode on the substrate; and an additional capping pattern on thesecond gate electrode, wherein the additional capping pattern comprisesa single-layered structure including the same material as that of theupper capping pattern, and wherein a first channel length in ahorizontal direction of a first channel region overlapping the firstgate electrode is less than a second channel length in the horizontaldirection of a second channel region overlapping the second gateelectrode.
 16. A semiconductor device comprising: a gate electrode on asubstrate; an upper capping pattern on the gate electrode and includinga body and a protrusion; a lower capping pattern between the gateelectrode and the upper capping pattern; and a plurality of gate spacerson corresponding side surfaces of the gate electrode, the plurality ofgate spacers spaced apart from each other with the gate electrodeinterleaved therebetween, wherein the lower capping pattern comprises: afirst portion between the gate electrode and the upper capping pattern;and a plurality of second portions extending from the first portion ontocorresponding side surfaces of the protrusion of the upper cappingpattern, wherein the upper capping pattern covers a topmost surface ofeach of the second portions, wherein side surfaces of the body of theupper capping pattern are aligned with side surfaces of the lowercapping pattern, and wherein each of the plurality of gate spacers is incontact with corresponding side surfaces of the body of the uppercapping pattern and corresponding side surfaces of the lower cappingpattern.